Liquid crystal display device

ABSTRACT

A liquid crystal display device includes a first substrate, a pixel electrode which is disposed on the first substrate and comprises a first sub-pixel electrode and a second sub-pixel electrode adjacent to the first sub-pixel electrode along a first direction, and a shielding electrode which is disposed on the same layer as the pixel electrode and comprises a first area having a first width and a second area having a second width which is smaller than the first width along a second direction which crosses the first direction, and the first sub-pixel electrode may be adjacent to the first area along the second direction, and the second sub-pixel electrode may be adjacent to the second area along the second direction.

This application claims priority to Korean Patent Application No.10-2016-0164346, filed on Dec. 5, 2016, all the benefits accruingtherefrom under 35 U.S.C. § 119, the content of which in its entirety isherein incorporated by reference.

BACKGROUND 1. Field

Exemplary embodiments of the invention relate to a liquid crystaldisplay (“LCD”) device.

2. Description of the Related Art

An LCD device is one of the most widely used types of flat panel displaydevices. Generally, the LCD device includes a pair of substrates havingfield generating electrodes, such as pixel electrodes and a commonelectrode, and a liquid crystal layer disposed between the twosubstrates. In the LCD device, generally, voltages are applied to thefield generating electrodes to generate an electric field in the liquidcrystal layer. Accordingly, the direction of liquid crystal molecules ofthe liquid crystal layer is determined, and polarization of incidentlight is controlled by the generated electric field. As a result, adesired image is displayed on the LCD device.

Among various types of LCD devices, an LCD device with a verticallyaligned (“VA”) mode, in which long axes of liquid crystals are alignedperpendicular to upper and lower display panels when no electric fieldis applied, is drawing a lot of attention due to a high contrast ratioand a wide reference viewing angle.

SUMMARY

Exemplary embodiments of the invention are directed to a liquid crystaldisplay (“LCD”) device having improved lateral visibility with minimizedreduction in aperture ratio.

However, exemplary embodiments of the invention are not restricted tothe one set forth herein. The above and other features of the exemplaryembodiments of the invention will become more apparent to one ofordinary skill in the art to which the exemplary embodiments of theinvention pertains by referencing the detailed description.

An exemplary embodiment discloses a liquid crystal display devicecomprising a first substrate, a pixel electrode which is disposed on thefirst substrate and comprises a first sub-pixel electrode and a secondsub-pixel electrode adjacent to the first sub-pixel electrode along afirst direction, and a shielding electrode which is disposed on the samelayer as the pixel electrode and comprises a first area having a firstwidth and a second area having a second width which is smaller than thefirst width along a second direction which crosses the first direction.The first sub-pixel electrode may be adjacent to the first area alongthe second direction, and the second sub-pixel electrode may be adjacentto the second area along the second direction.

An exemplary embodiment also discloses an LCD device comprising a firstsubstrate, a pixel electrode which is disposed on the first substrateand comprises a first sub-pixel electrode and a second sub-pixelelectrode adjacent to the first sub-pixel electrode in a firstdirection, a second substrate which faces the first substrate, and ablack matrix which is disposed on the second substrate. The black matrixmay do not overlap the first sub-pixel electrode and at least partiallyoverlap the second sub-pixel electrode in a direction perpendicular to amajor surface plane defining the first substrate.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other advantages and features of this disclosure willbecome apparent and more readily appreciated from the followingdescription of the embodiments, taken in conjunction with theaccompanying drawings in which:

FIG. 1 is a schematic plan view of an exemplary embodiment of a pixelincluded in a liquid crystal display (“LCD”) device;

FIG. 2 is a plan view of an exemplary embodiment of a gate conductorillustrated in FIG. 1;

FIG. 3 is a plan view of an exemplary embodiment of a data conductorillustrated in FIG. 1;

FIG. 4 is a plan view of an exemplary embodiment of a pixel electrodeand a shielding electrode illustrated in FIG. 1;

FIG. 5 is a plan view of an exemplary embodiment of the pixel electrode,the shielding electrode and a black matrix illustrated in FIG. 1;

FIG. 6 is a plan view of an exemplary embodiment of a common electrodeillustrated in FIG. 1;

FIG. 7 is a cross-sectional view taken along line I1-I1′ of FIG. 1;

FIG. 8 is a cross-sectional view taken along line I2-I2′ of FIG. 1;

FIG. 9A is an enlarged view of an exemplary embodiment of an area Aillustrated in FIG. 1;

FIG. 9B is an enlarged view of an exemplary embodiment of an area Billustrated in FIG. 9A;

FIG. 9C is an enlarged view of an exemplary embodiment of an area Cillustrated in FIG. 9A;

FIG. 9D is an enlarged view of an exemplary embodiment of an area Dillustrated in FIG. 9A;

FIG. 9E is an enlarged view of an exemplary embodiment of an area Eillustrated in FIG. 9A;

FIG. 10 is a cross-sectional view taken along line II1-II1′ of FIG. 9A;

FIG. 11 is a cross-sectional view taken along line II2-II2′ of FIG. 9A;

FIG. 12 is a graph illustrating transmittance versus gray level of anexemplary embodiment of an LCD device;

FIGS. 13 through 16 are schematic plan views of other exemplaryembodiments of pixels included in LCD devices;

FIG. 17 is a graph illustrating transmittance versus gray level of anexemplary embodiment of the LCD device of FIG. 16

FIG. 18 is a schematic plan view of an exemplary embodiment of a pixelincluded in an LCD device of FIG. 1:

FIG. 19 is a schematic plan view of another exemplary embodiment of apixel included in an LCD; and

FIG. 20 is a graph illustrating transmittance versus gray level of anexemplary embodiment of the LCD device of FIG. 19.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments. It is apparent, however,that various exemplary embodiments may be practiced without thesespecific details or with one or more equivalent arrangements. In otherinstances, well-known structures and devices are shown in block diagramform in order to avoid unnecessarily obscuring various exemplaryembodiments.

In the accompanying figures, the size and relative sizes of layers,films, panels, regions, etc., may be exaggerated for clarity anddescriptive purposes. Also, like reference numerals denote likeelements.

When an element or layer is referred to as being “on,” “connected to,”or “coupled to” another element or layer, it may be directly on,connected to, or coupled to the other element or layer or interveningelements or layers may be present. When, however, an element or layer isreferred to as being “directly on,” “directly connected to,” or“directly coupled to” another element or layer, there are no interveningelements or layers present. As used herein, connected may refer toelements being physically and/or electrically connected to each other.”For the purposes of this disclosure, “at least one of X, Y, and Z” and“at least one selected from the group consisting of X, Y, and Z” may beconstrued as X only, Y only, Z only, or any combination of two or moreof X, Y, and Z, such as, for instance, XYZ, XYY, YZ, and ZZ. Likenumbers refer to like elements throughout. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

Although the terms first, second, etc. may be used herein to describevarious elements, components, regions, layers, and/or sections, theseelements, components, regions, layers, and/or sections should not belimited by these terms. These terms are used to distinguish one element,component, region, layer, and/or section from another element,component, region, layer, and/or section. Thus, a first element,component, region, layer, and/or section discussed below could be termeda second element, component, region, layer, and/or section withoutdeparting from the teachings of the present disclosure.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper,” and the like, may be used herein for descriptive purposes, and,thereby, to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the drawings. Spatiallyrelative terms are intended to encompass different orientations of anapparatus in use, operation, and/or manufacture in addition to theorientation depicted in the drawings. For example, if the apparatus inthe drawings is turned over, elements described as “below” or “beneath”other elements or features would then be oriented “above” the otherelements or features. Thus, the exemplary term “below” can encompassboth an orientation of above and below. Furthermore, the apparatus maybe otherwise oriented (e.g., rotated 90 degrees or at otherorientations), and, as such, the spatially relative descriptors usedherein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. “Or” means “and/or.” As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, 20%, 10% or 5% of the stated value.

Various exemplary embodiments are described herein with reference tosectional illustrations that are schematic illustrations of idealizedexemplary embodiments and/or intermediate structures. As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments disclosed herein should not beconstrued as limited to the particular illustrated shapes of regions,but are to include deviations in shapes that result from, for instance,manufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionprovided by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the drawings are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to be limiting.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and will not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

Hereinafter, exemplary embodiments will be described with reference tothe accompanying drawings.

FIG. 1 is a schematic plan view of an exemplary embodiment of a pixelincluded in a liquid crystal display (“LCD”) device. In FIG. 1, a blackmatrix BM is illustrated with only the boundary line thereof such thatthe black matrix BM can be distinguished from other elements.

Referring to FIG. 1, an LCD device according to an exemplary embodimentmay include a pixel PX, a common electrode CE (refer FIG. 7), ashielding electrode 180, a first scan line SL1, a second scan line SL2,a first data line DL1, and the black matrix BM.

The first scan line SL1 and the second scan line SL2 may extend in afirst direction d1. The first data line DL1 may extend in a seconddirection d2. In an exemplary embodiment, the first direction d1 maycross the second direction d2. In FIG. 1, for example, the firstdirection d1 is a row direction of the LCD device, and the seconddirection d2 is a column direction of the LCD device. For ease ofdescription, a scan line located above a pixel electrode PE will bereferred to as the first scan line SL1, and a scan line located underthe pixel electrode PE will be referred to as the second scan line SL2.

The pixel PX may include a switching device TR and the pixel electrodePE. In an exemplary embodiment, the switching device TR may be athree-terminal device such as a thin-film transistor (“TFT”).Hereinafter, a case where the switching device TR is a TFT will bedescribed as an example.

The switching device TR may have a gate electrode GE electricallyconnected to the second scan line SL2 and a source electrode SEelectrically connected to the first data line DL1. In addition, a drainelectrode DE of the switching device TR may be electrically connected tothe pixel electrode PE.

The switching device TR may perform a switching operation, according toa scan signal received from the second scan line SL2, thereby providinga data signal received from the first data line DL1 to the pixelelectrode PE. Although a case where the gate electrode GE of theswitching device TR is electrically connected to the second scan lineSL2 is described herein as an example, the gate electrode GE of theswitching device TR can also be electrically connected to the first scanline SL1 instead of the second scan line SL2 in another exemplaryembodiment.

In an exemplary embodiment, the pixel electrode PE may extend further inthe first direction d1 than in the second direction d2. The pixelelectrode PE includes at least two sub-pixel electrodes. Here, one ofthe two sub-pixel electrodes overlaps the black matrix BM in a directionperpendicular to a major surface plane defining a lower substrate 110(refer FIG. 7), and the other sub-pixel electrode does not overlap theblack matrix BM in the direction perpendicular to the major surfaceplane defining the lower substrate 110. Hereinafter, a case where thepixel electrode PE includes first through fourth sub-pixel electrodesSPE1 through SPE4 will be described as an example.

The first through fourth sub-pixel electrodes SPE1 through SPE4 may bearranged in the first direction d1 with an order of the first throughfourth sub-pixel electrodes SPE1 through SPE4. Each of the first throughfourth sub-pixel electrodes SPE1 through SPE4 may be directly connectedto one or two of the other sub-pixel electrodes. Each of the firstthrough fourth sub-pixel electrodes SPE1 through SPE4 may include aplate portion and branch portions.

Here, at least part of each of the first sub-pixel electrode SPE1 andthe fourth sub-pixel electrode SPE4 may not overlap the black matrix BMin the direction perpendicular to the major surface plane defining thelower substrate 110. In addition, each of the second sub-pixel electrodeSPE2 and the third sub-pixel electrode SPE3 may overlap the black matrixBM in the direction perpendicular to the major surface plane definingthe lower substrate 110. The shapes of the first through fourthsub-pixel electrodes SPE1 through SPE4 will be described later withreference to FIGS. 4 to 6.

In an exemplary embodiment, a shielding electrode 180 may overlap atleast one of the first scan line SL1, the second scan line SL2, and thefirst data line DL1 in the direction perpendicular to the major surfaceplane defining the lower substrate 110. The shielding electrode 180 mayblock coupling between the pixel electrode PE and at least one of thefirst scan line SL1, the second scan line SL2 and the first data lineDL1. The shape of the shielding electrode 180 will be described laterwith reference to FIGS. 4 and 5.

The common electrode CE (refer FIG. 7) may define a plurality of slitportions. Here, the slit portions may include first through fourth slitportions SLT1 through SLT4 corresponding to the first through fourthsub-pixel electrodes SPE1 through SPE4. The common electrode CE will bedescribed later with reference to FIG. 6.

FIG. 2 is a plan view of an exemplary embodiment of a gate conductor GWillustrated in FIG. 1. FIG. 3 is a plan view of an exemplary embodimentof a data conductor DW illustrated in FIG. 1. FIG. 4 is a plan view ofan exemplary embodiment of the pixel electrode PE and the shieldingelectrode 180 illustrated in FIG. 1. FIG. 5 is a plan view of anexemplary embodiment of the pixel electrode PE, the shielding electrode180 and the black matrix BM illustrated in FIG. 1. FIG. 6 is a plan viewof an exemplary embodiment of the common electrode CE illustrated inFIG. 1. FIG. 7 is a cross-sectional view taken along line I1-I1′ ofFIG. 1. FIG. 8 is a cross-sectional view taken along line I2-I2′ of FIG.1.

Referring to FIGS. 2 through 8, a lower display panel 10 may be placedto face an upper display panel 20. A liquid crystal layer 30 may beinterposed between the lower display panel 10 and the upper displaypanel 20. The liquid crystal layer 30 may include a plurality of liquidcrystal molecules 31. In an exemplary embodiment, the lower displaypanel 10 may be bonded to the upper display panel 20 by sealing.

Hereinafter, the lower display panel 10 will be described.

In an exemplary embodiment, the lower substrate 110 may be a transparentinsulating substrate. In an exemplary embodiment, the transparentinsulating substrate may be a glass substrate, a quartz substrate, atransparent resin substrate, or the like. In an exemplary embodiment,the lower substrate 110 may be flexible.

The gate conductor GW may be disposed on the lower substrate 110. Thegate conductor GW may include the gate electrode GE and a plurality ofscan lines including the first scan line SL1 and the second scan lineSL2. The first scan line SL1 may extend on the lower substrate 110 alongthe first direction d1. The first scan line SL1 may be adjacent to thesecond scan line SL2.

The gate electrode GE may be disposed on the lower substrate 110 andconnected to the second scan line SL2. The gate electrode GE may branchfrom the second scan line SL2. The gate electrode GE is one element ofthe switching device TR.

In an exemplary embodiment, the gate conductor GW may be a single layer,a double layer or a triple layer made of one conductive metal, at leasttwo conductive metals or three conductive metals selected from aluminum(Al), copper (Cu), molybdenum (Mo), chrome (Cr), titanium (Ti), tungsten(W), molybdenum tungsten (MoW), molybdenum titanium (MoTi), andcopper/molybdenum titanium (Cu/MoTi), for example. In an exemplaryembodiment, the elements of the gate conductor GW may be disposedsimultaneously by the same mask process, for example.

A gate insulating layer 120 may be disposed on the gate conductor GW. Inan exemplary embodiment, the gate insulating layer 120 may be made ofsilicon nitride (SiNx) or silicon oxide (SiOx), for example. In anexemplary embodiment, the gate insulating layer 120 may also have amultilayer structure composed of at least two insulating layers withdifferent physical characteristics.

The data conductor DW may be disposed on the gate insulating layer 120.The data conductor DW may include a semiconductor layer 130, the firstdata line DL1, the source electrode SE, and the drain electrode DE.

The semiconductor layer 130 may include a channel area 130 a which formsa channel of the switching device TR. In an exemplary embodiment, thesemiconductor layer 130 may include amorphous silicon or polycrystallinesilicon, for example. In addition, the semiconductor layer 130 mayinclude an oxide semiconductor. In an exemplary embodiment, the oxidesemiconductor may be one of In—Ga-Zinc-Oxide (IGZO), ZnO, ZnO₂, CdO,SrO, SrO₂, CaO, CaO₂, MgO, MgO₂, InO, In₂O₂, GaO, Ga₂O, Ga₂O₃, SnO,SnO₂, GeO, GeO₂, PbO, Pb₂O₃, Pb₃O₄, TiO, TiO₂, Ti₂O₃, and Ti₃O₅, forexample.

The data conductor DW may further include an ohmic contact layer 140.The ohmic contact layer 140 may be disposed on the semiconductor layer130. In an exemplary embodiment, the ohmic contact layer 140 may be madeof a material such as n+ hydrogenated amorphous silicon heavily dopedwith an n-type impurity such as phosphorous or may be made of silicide.When the semiconductor layer 130 is made of an oxide semiconductor, theohmic contact layer 140 may be omitted.

The first data line DL1, the source electrode SE and the drain electrodeDE may be disposed on the gate insulating layer 120 and the ohmiccontact layer 140. The first data line DL1 may extend on the lowersubstrate 110 along the second direction d2.

The source electrode SE may branch from the first data line DL1, and atleast part of the source electrode SE may overlap the gate electrode GEin the direction perpendicular to the major surface plane defining thelower substrate 110. The drain electrode DE may overlap the gateelectrode GE in the direction perpendicular to the major surface planedefining the lower substrate 110 and may be separated from the sourceelectrode SE by a predetermined distance. In FIG. 1, the sourceelectrode SE is U-shaped, and the drain electrode DE is surrounded bythe source electrode SE, for example. However, the arrangements of thesource electrode SE and the drain electrode DE are not limited to thisexample.

The source electrode SE and the drain electrode DE form the switchingdevice TR together with the channel area 130 a of the semiconductorlayer 130 and the gate electrode GE. The source electrode SE of theswitching device TR may be connected to the first data line DL1. Thedrain electrode DE of the switching device TR may be connected to thepixel electrode PE via a contact hole CNT.

In an exemplary embodiment, the data conductor DW may be a single layer,a double layer or a triple layer made of one conductive metal, at leasttwo conductive metals or three conductive metals selected from aluminum(Al), copper (Cu), molybdenum (Mo), chrome (Cr), titanium (Ti), tungsten(W), molybdenum tungsten (MoW), molybdenum titanium (MoTi), andcopper/molybdenum titanium (Cu/MoTi), for example. However, the materialthat forms the data conductor DW is not limited to the above examples,and the data conductor DW can be made of various metals or conductors.In an exemplary embodiment, the elements of the data conductor DW may bedisposed simultaneously by the same mask process, for example. In anexemplary embodiment, the first data line DL1, the source electrode SEand the drain electrode DE may have substantially the same shape as thesemiconductor layer 130 except for the channel area 130 a.

A first passivation layer 150 may be disposed on the first data lineDL1, the source electrode SE, and the drain electrode DE. In anexemplary embodiment, the first passivation layer 150 may be made of aninorganic insulating material such as silicon nitride or silicon oxide.The first passivation layer 150 may prevent a pigment of an organicinsulating layer 160, which will be described later, from flowing intothe channel area 130 a.

The organic insulating layer 160 may be disposed on the firstpassivation layer 150. The organic insulating layer 160 may include anorganic material having relatively superior planarizationcharacteristics and photosensitivity. The organic insulating layer 160may be a color filter in an exemplary embodiment, when the organicinsulating layer 160 is a color filter, it may display one of threeprimary colors such as red, green, and blue. Furthermore, a color filterCF disposed on the upper display panel 20 to be described later may beomitted. In an alternative embodiment, the organic insulating layer 160,instead of the color filter CF, may be omitted. Hereinafter, a casewhere the organic insulating layer 160 is not a color filter will bedescribed as an example.

A second passivation layer 170 may be disposed on the organic insulatinglayer 160. In an exemplary embodiment, the second passivation layer 170may be made of an inorganic insulating material such as silicon nitrideor silicon oxide. In an exemplary embodiment, the second passivationlayer 170 may prevent the organic insulating layer 160 from being liftedand prevent the liquid crystal layer 30 from being contaminated by asubstance such as a solvent flowing from the organic insulating layer160.

The contact hole CNT which exposes at least part of the drain electrodeDE may be defined in the first passivation layer 150, the organicinsulating layer 160 and the second passivation layer 170.

The pixel electrode PE may be disposed on the second passivation layer170. In an exemplary embodiment, the pixel electrode PE may be made of atransparent conductive material such as indium tin oxide (“ITO”) orindium zinc oxide (“IZO”) or a reflective metal such as aluminum,silver, chrome or an alloy of these metals, for example. The pixelelectrode PE contacts the drain electrode DE through the contact holeCNT.

Hereinafter, the shape of the pixel electrode PE will be described indetail with reference to FIGS. 1 through 4.

The pixel electrode PE may include a contact portion CT and the firstthrough fourth sub-pixel electrodes SPE1 through SPE4 which areconnected to the contact portion CT.

The contact portion CT is defined as an area of the pixel electrode PE,which contacts the exposed drain electrode DE directly through thecontact hole CNT. The contact portion CT is directly connected to thefirst sub-pixel electrode SPE1. Accordingly, the contact portion CTelectrically and physically connects the drain electrode DE and thefirst sub-pixel electrode SPE1.

The first sub-pixel electrode SPE1 may include a first plate portionSPE1 a and a plurality of first branch portions SPE1 b. In an exemplaryembodiment, the first plate portion SPE1 a may have a rhombic plateshape, for example. Here, the plate shape refers to a single unitaryindivisible plate shape. The first branch portions SPE1 b may extendfrom the first plate portion SPE1 a. In an exemplary embodiment, thefirst branch portions SPE1 b may extend from at least one of four edgesof the rhombic first plate portion SPE1 a, for example.

The second sub-pixel electrode SPE2 may include a second plate portionSPE2 a and a plurality of second branch portions SPE2 b. In an exemplaryembodiment, the second plate portion SPE2 a may have a rhombic plateshape, for example. The second branch portions SPE2 b may extend fromthe second plate portion SPE2 a. In an exemplary embodiment, the secondbranch portions SPE2 b may extend from at least one of four edges of therhombic second plate portion SPE2 a, for example.

The third sub-pixel electrode SPE3 may include a third plate portionSPE3 a and a plurality of third branch portions SPE3 b. In an exemplaryembodiment, the third sub-pixel electrode SPE3 may have the same shapeas the second sub-pixel electrode SPE2, for example. The fourthsub-pixel electrode SPE4 may include a fourth plate portion SPE4 a and aplurality of fourth branch portions SPE4 b. In an exemplary embodiment,the fourth sub-pixel electrode SPE4 may have the same shape as the firstsub-pixel electrode SPE1, for example.

The first through fourth sub-pixel electrodes SPE1 through SPE4 areseparated from each other by a predetermined distance and each of thefirst through fourth sub-pixel electrodes SPE1 through SPE4 is directlyconnected to one or two of the other sub-pixel electrodes among thefirst through fourth sub-pixel electrodes SPE1 through SPE4. In anexemplary embodiment, the first plate portion SPE1 a may be connected tothe second plate portion SPE2 a, and the second plate portion SPE2 a maybe connected to the first plate portion SPE1 a and the third plateportion SPE3 a. In addition, the third plate SPE3 a may be connected tothe second plate portion SPE2 a and the fourth plate portion SPE4 a, forexample. In an alternative embodiment, branch portions included in eachsub-pixel electrode, instead of the plate portions, can be connected tobranch portions included in an adjacent sub-pixel electrode. A distanceti between the first sub-pixel electrode SPE1 and the second sub-pixelelectrode SPE2 may be about 3 micrometers (μm) in an exemplaryembodiment. In addition, a distance between the second sub-pixelelectrode SPE2 and the third sub-pixel electrode SPE3 and a distancebetween the third sub-pixel electrode SPE3 and the fourth sub-pixelelectrode SPE4 may be equal to the distance t1 between the firstsub-pixel electrode SPE1 and the second sub-pixel electrode SPE2 in anexemplary embodiment.

The area of the first sub-pixel electrode SPE1 may be smaller than thatof the second sub-pixel electrode SPE2. The area of the first sub-pixelelectrode SPE1 may be substantially equal to the area of the fourthsub-pixel electrode SPE1. In addition, the area of the second sub-pixelelectrode SPE2 may be substantially equal to the area of the thirdsub-pixel electrode SPE3. This will be described in more detail based onthe first sub-pixel electrode SPE1 and the second sub-pixel electrodeSPE2.

A vertical length h1 of the first sub-pixel electrode SPE1 is smallerthan a vertical length h2 of the second sub-pixel electrode SPE2. Incontrast, a horizontal length l1 of the first sub-pixel electrode SPE1may be substantially equal to a horizontal length l2 of the secondsub-pixel electrode SPE2.

In an exemplary embodiment, a difference between the vertical length h1of the first sub-pixel electrode SPE1 and the vertical length h2 of thesecond sub-pixel electrode SPE2 may be about 7.5 μm for example. In anexemplary embodiment, the horizontal length l1 of the first sub-pixelelectrode SPE1 and the horizontal length l2 of the second sub-pixelelectrode SPE2 may be about 41.5 μm, for example. However, as long asthe vertical length h1 of the first sub-pixel electrode SPE1 is smallerthan the vertical length h2 of the second sub-pixel electrode SPE2, theindividual values of the vertical length h1 and the horizontal length l1of the first sub-pixel electrode SPE1 and the vertical length h2 and thehorizontal length l2 of the second sub-pixel electrode SPE2 are notparticularly limited.

The shielding electrode 180 is disposed on the same layer as the pixelelectrode PE. In an exemplary embodiment, the shielding electrode 180may be made of a transparent conductive material such as ITO or IZO or areflective metal such as aluminum, silver, chrome or an alloy of thesemetals. In an exemplary embodiment, the shielding electrode 180 and thepixel electrode PE may be disposed simultaneously by the same maskprocess, for example.

Hereinafter, the shielding electrode 180 will be described in moredetail. The shielding electrode 180 may include first through thirdsub-shielding electrodes 180 a through 180 c.

The first sub-shield electrode 180 a may at least partially overlap thefirst scan line SL1. That is, the first sub-shielding electrode 180 a isan area of the shielding electrode 180 which extends in the firstdirection d1 and at least partially overlaps the first scan line SL1.The second sub-shielding electrode 180 b may at least partially overlapthe second scan line SL2. That is, the second sub-shielding electrode180 b is an area of the shielding electrode 180 which extends in thefirst direction d1 and at least partially overlaps the second scan lineSL2. The third sub-shield electrode 180 c may at least partially overlapthe first data line DL1. That is, the third sub-shielding electrode 180c is an area of the shielding electrode 180 which extends in the seconddirection d2 and at least partially overlaps the first data line DL1.

Each of the first through third sub-shield electrodes 180 a through 180c is connected to one or two of the other sub-shield electrodes. In anexemplary embodiment, the shielding electrode 180 may be provided withthe same voltage as the voltage provided to the common electrode CE, forexample.

Hereinafter, the relationship between the shielding electrode 180 andthe pixel electrode PE is described using the first sub-shieldingelectrode 180 a, the first sub-pixel electrode SPE1 and the secondsub-pixel electrode SPE2 as an example.

The first sub-shielding electrode 180 a may include areas havingdifferent widths. Hereinafter, an area having a first width w1 andadjacent to the first sub-pixel electrode SPE1 along the seconddirection d2 will be defined as a first area 180 a 1. In addition, anarea having a second width w2 and adjacent to the second sub-pixelelectrode SPE2 along the second direction d2 will be defined as a secondarea 180 a 2. In other words, the first area 180 a 1 is an area of thefirst sub-shielding electrode 180 a, facing the first sub-pixelelectrode SPE1. In addition, the second area 180 a 2 is an area of thefirst sub-shielding electrode 180 a, facing the second sub-pixelelectrode SPE2.

More specifically, the first area 180 a 1 of the first sub-shieldingelectrode 180 a has the first width w1 which is a distance from one sideof the first area 180 a 1 to the other side opposite to the one side inthe second direction d2. The second area 180 a 2 of the firstsub-shielding electrode 180 a has the second width w2 which is adistance from one side of the second area 180 a 2 to the other sideopposite to the one side in the second direction d2. Here, the firstwidth w1 is greater than the second width w2.

The first width w1 may be about 11.5 μm in an exemplary embodiment, forexample. Also, the second width w2 may be about 4 μm in an exemplaryembodiment, for example. Accordingly, a difference between the firstwidth w1 and the second width w2 may be about 7.5 μm in an exemplaryembodiment, for example. However, as long as the first width w1 isgreater than the second width w2, the individual values of the firstwidth w1 and the second width w2 are not particularly limited.

The first sub-shielding electrode 180 a is separated from each of thefirst sub-pixel electrode SPE1 and the second sub-pixel electrode SPE2by predetermined distances. Here, a space between the first area 180 a 1of the first sub-shielding electrode 180 a and the first sub-pixelelectrode SPE1 is defined as a first spacing area G1. In addition, aspace between the second area 180 a 2 of the first sub-shieldingelectrode 180 a and the second sub-pixel electrode SPE2 is defined as asecond spacing area G2. The first sub-pixel electrode SPE1 and thesecond sub-pixel electrode SPE2 are not disposed in the first spacingarea G1 and the second spacing area G2, respectively. The first spacingarea G1 and the second spacing area G2 will be described later withreference to FIG. 5.

The pixel electrode PE may be disposed on the same layer as theshielding electrode 180. Furthermore, the shielding electrode 180 andthe pixel electrode PE are insulated from each other. The verticallength h2 of the second sub-pixel electrode SPE2 is greater than thevertical length h1 of the first sub-pixel electrode SPE1. Thus, thesecond area 180 a 2 of the first sub-shielding electrode 180 a may berecessed in a third direction d3 by an amount of a difference betweenthe vertical length h2 of the second sub-pixel electrode SPE2 and thevertical length h1 of the first sub-pixel electrode SPE1. This can bereflected as the second width w2 of the second area 180 a 2 is smallerthan the first width w1 of the first area 180 a 1.

In contrast, the second sub-shielding electrode 180 b may be provided tohave a uniform width. In an exemplary embodiment, the width of thesecond sub-shielding electrode 180 b may be equal to the first width w1,for example.

Although not illustrated in the drawings, a first alignment layer may bedisposed on the pixel electrode PE and the shielding electrode 180. Inan exemplary embodiment, the first alignment layer may be made of, e.g.,polyimide.

Hereinafter, the upper display panel 20 will be described.

An upper substrate 210 may be placed to face the lower substrate 110. Inan exemplary embodiment, the upper substrate 210 may be made oftransparent glass or plastic, for example. In an exemplary embodiment,the upper substrate 210 may be made of the same material as the lowersubstrate 110, for example.

The black matrix BM may be disposed on the upper substrate 210. Theblack matrix BM disposed on the upper substrate 210 may block light fromtransmitting through areas other than a pixel area. In an exemplaryembodiment, the black matrix BM may be made of a metal materialincluding organic matter or chrome, for example.

In a pixel electrode including at least two sub-pixel electrodes, theblack matrix BM at least partially overlaps one of the sub-pixelelectrodes but does not overlap the other sub-pixel electrode.

Referring to FIGS. 1 and 5, the black matrix BM may not overlap thefirst sub-pixel electrode SPE1 and the fourth sub-pixel electrode SPE4in the direction perpendicular to the major surface plane defining thelower substrate 110. In contrast, the black matrix BM may overlap atleast part of each of the second sub-pixel electrode SPE2 and the thirdsub-pixel electrode SPE3 in the direction perpendicular to the majorsurface plane defining the lower substrate 110. Hereinafter, this willbe described based on the first sub-pixel electrode SPE1 and the secondsub-pixel electrode SPE2.

The black matrix BM may not overlap the first sub-pixel electrode SPE1in the direction perpendicular to the major surface plane defining thelower substrate 110. In contrast, the black matrix BM may completelyoverlap the first area 180 a 1 of the first sub-shielding electrode 180a in the direction perpendicular to the major surface plane defining thelower substrate 110. In addition, the black matrix BM may overlap atleast part of the first spacing area G1 or may not overlap the firstspacing area G1.

The black matrix BM may overlap at least part of the second sub-pixelelectrode SPE2 in the direction perpendicular to the major surface planedefining the lower substrate 110. The first scan line SL1 may alsooverlap at least part of the second sub-pixel electrode SPE2 in thedirection perpendicular to the major surface plane defining the lowersubstrate 110.

The black matrix BM may completely overlap the second area 180 a 2 ofthe first sub-shielding electrode 180 a in the direction perpendicularto the major surface plane defining the lower substrate 110. Inaddition, the black matrix BM may completely overlap the second spacingarea G2.

Accordingly, the black matrix BM may completely cover liquid crystalmolecules located in the second spacing area G2 among the liquid crystalmolecules 31. This will be described later with reference to FIG. 9Athrough 9E.

The color filter CF may be disposed on the black matrix BM and the uppersubstrate 210. In an exemplary embodiment, the color filter CF mayrepresent, but not limited to, one of three primary colors such as red,green, and blue. The color filter CF may be made of a material thatdisplays different colors in adjacent pixels.

A planarization layer 220 may be disposed on the color filter CF and theblack matrix BM. In an exemplary embodiment, the planarization layer 220may be made of an insulating material and may be omitted in some cases.

The common electrode CE may be disposed on the planarization layer 220.The common electrode CE may overlap the pixel electrode PE in thedirection perpendicular to the major surface plane defining the lowersubstrate 110. In an exemplary embodiment, the common electrode CE maybe made of a transparent conductive material such as ITO or IZO or areflective metal such as aluminum, silver, chromium or an alloy of thesemetals.

Referring to FIG. 6, the common electrode CE may defined the firstthrough fourth slit portions SLT1 through SLT4. If the common electrodeCE is made of a transparent conductive material, the first throughfourth slit portions SLT1 through SLT4 may be defined as areas in whichno transparent conductive material is disposed.

The first through fourth slit portions SLT1 through SLT4 mayrespectively overlap the first through fourth sub-pixel electrodes SPE1through SPE4 in the direction perpendicular to the major surface planedefining the lower substrate 110. In an exemplary embodiment, each ofthe first through fourth slit portions SLT1 through SLT4 may becross-shaped, for example. The first slit portion SLT1 may have the sameshape and size as the fourth slit portion SLT4 in an exemplaryembodiment. The second slit portion SLT2 may have the same shape andsize as the third slit portion SLT3 in an exemplary embodiment.

Hereinafter, the relationship between the pixel electrode PE and thecommon electrode CE will be described with reference to FIGS. 1, 4 and 6based on the first sub-pixel electrode SPE1, the second sub-pixelelectrode SPE2, the first slit portion SLT1 and the second slit portionSLT2.

In an exemplary embodiment, a vertical length hs1 of the first slitportion SLT1 is smaller than a vertical length hs2 of the second slitportion SLT2. In contrast, a horizontal length ls1 of the first slitportion SLT1 may be equal to a horizontal length ls2 of the second slitportion SLT2. In an exemplary embodiment, the vertical length hs1 andthe horizontal length ls1 of the first slit portion SLT1 may correspondto the vertical length h1 and the horizontal length l1 of the firstsub-pixel electrode SPE1, respectively. In an exemplary embodiment, thevertical length hs2 and the horizontal length ls2 of the second slitportion SLT2 may correspond to the vertical length h2 and the horizontallength l2 of the second sub pixel electrode SPE2, respectively.

Although not illustrated in the drawings, a second alignment layer maybe disposed on the common electrode CE. In an exemplary embodiment, thesecond alignment layer may be made of, e.g., polyimide.

Hereinafter, the liquid crystal layer 30 will be described.

The liquid crystal layer 30 includes the liquid crystal molecules 31having negative dielectric anisotropy. In an exemplary embodiment, theliquid crystal molecules 31 may change the polarization of light byrotating or tilting in a specific direction when an electric field isprovided between the lower substrate 110 and the upper substrate 210.

FIG. 9A is an enlarged view of an exemplary embodiment of an area Aillustrated in FIG. 1. FIG. 9B is an enlarged view of an exemplaryembodiment of an area B illustrated in FIG. 9A. FIG. 9C is an enlargedview of an exemplary embodiment of an area C illustrated in FIG. 9A.FIG. 9D is an enlarged view of an exemplary embodiment of an area Dillustrated in FIG. 9A. FIG. 9E is an enlarged view of an exemplaryembodiment of an area E illustrated in FIG. 9A. FIG. 10 is across-sectional view taken along line II1-II1′ of FIG. 9A. FIG. 11 is across-sectional view taken along line II2-II2′ of FIG. 9A. For ease ofdescription, FIGS. 10 and 11 illustrate mainly the pixel electrode PE,the common electrode CE, the black matrix BM, and the shieldingelectrode 180.

Referring to FIGS. 1 and 9 through 11, the LCD device may furtherinclude an electric field area EF. The electric field area EF may beadjacent to the first spacing area G1 in the first direction d1 and tothe second spacing area G2 in the second direction d2. As describedabove, the pixel electrode PE is not disposed in the first spacing areaG1 and the second spacing area G2 In contrast, at least part of thesecond sub-pixel electrode SPE2 is disposed in the electric field areaEF.

Hereinafter, one of liquid crystal molecules located in the firstspacing area G1 will be referred to as a first liquid crystal molecule31 a, one of liquid crystal molecules located in the second spacing areaG2 will be referred to as a second liquid crystal molecule 31 b, and oneof liquid crystal molecules located in the electric field area EF willbe referred to as a third liquid crystal molecule 31 c.

When an electric field is provided between the pixel electrode PE andthe common electrode CE, the first through third liquid crystalmolecules 31 a through 31 c are tilted at predetermined angles accordingto the electric field.

The first sub-pixel electrode SPE1 is not disposed in the first spacingarea G1. Accordingly, the first liquid crystal molecule 31 a disposed inthe first spacing area G1 is tilted at an azimuth of about 90 degrees tothe first direction d1 in a plain view of the LCD device when anelectric field E1 is provided between an end of the first sub-pixelelectrode SPE1 and the common electrode CE.

The second sub-pixel electrode SPE2 is not disposed in the secondspacing area G2. Accordingly, the second liquid crystal molecule 31 b isfitted at an azimuth of about 90 degrees to the first direction d1 in aplain view of the LCD device when an electric field E2 is providedbetween an end of the second sub-pixel electrode SPE2 and the commonelectrode CE.

In contrast, at least part of the second sub-pixel electrode SPE2 isdisposed in the electric field area EF. Accordingly, the third liquidcrystal molecule 31 c is tilted at an azimuth of about 45 degrees orabout 135 degrees in a plain view of the LCD device when an electricfield is provided between the at least part of the second sub-pixelelectrode SPE2 and the common electrode CE.

More specifically, the second branch portions SPE2 b may include branchportions extending from the second plate portion SPE2 a in a fourthdirection d4 and branch portions extending from the second plate portionSPE2 a in a fifth direction d5. In addition, the electric field area EFmay include a first sub-electric field area EFa which corresponds to thebranch portions extending from the second plate portion SPE2 a in thefourth direction d4 and a second sub-electric field area EFb whichcorresponds to the branch portions extending from the second plateportion SPE2 a in the fifth direction d5.

Among the third liquid crystal molecules 31 c, a liquid crystal molecule31 c 1 disposed in the first sub-field area EFa may be tilted at apredetermined azimuth when an electric field is provided by the branchportions extending from the second branch portions SPE2 b in the fourthdirection d4, the second plate portion SPE2 a, the second slit portionSLT2 and the common electrode CE. More specifically, the liquid crystalmolecule 31 c 1 may be tilted at an azimuth a of about 45 degrees to thefirst direction d1.

In addition, among the third liquid crystal molecules 31 c, a liquidcrystal molecule 31 c 2 disposed in the second sub-field area EFb may betilted at a predetermined azimuth when an electric field is provided bythe branch portions extending from the second branch portions SPE2 b inthe fifth direction d5, the second plate portion SPE2 a, the second slitportion SLT2 and the common electrode CE. More specifically, the liquidcrystal molecule 31 c 2 may be tilted at an azimuth b of about 135degrees to the first direction d1.

Referring to FIG. 10, only at least part of the first spacing area G1may be overlapped by the black matrix BM. In contrast, referring to FIG.11, the second spacing area G2 may be entirely overlapped by the blackmatrix BM. Accordingly, the second liquid crystal molecule 31 b disposedin the second spacing area G2 may be overlapped by the black matrix BM.

Generally, if a liquid crystal molecule tilted at an azimuth of about 90degrees to the first direction d1 is viewed from a side of the LCDdevice, which corresponds to the first direction d1, when the LCD devicedisplays an image of a low gray level, a side surface of the liquidcrystal molecule is observed. Since light can be leaked through theobserved side surface of the liquid crystal molecule, it may reducevisibility of the image from the side view. In contrast, if a liquidcrystal molecule tilted at an azimuth of about 0 degrees to the firstdirection d1 is viewed from the side of the LCD device, whichcorresponds to the first direction d1, when the LCD device displays animage of a low gray level, an end of the liquid crystal molecule may beobserved. Therefore, it may improve visibility of the image from theside view.

Generally, in an image of a high gray level, transmittance may increaseas the azimuth of a liquid crystal molecule is closer to about 90degrees with respect to the first direction d1. In contrast,transmittance may decrease as the azimuth of the liquid crystal moleculeis closer to about 0 degrees with respect to the first direction d1.

Referring back to FIG. 9A, as described above, the second liquid crystalmolecule 31 b disposed in the second spacing area G2 is tilted at anazimuth of about 90 degrees to the first direction d1 at a low graylevel. However, the second spacing area G2 is overlapped by the blackmatrix BM. Accordingly, the light leaked by the second liquid crystalmolecule 31 b located in the second spacing area G2 is prevented fromgoing outside the LCD device by the black matrix BM. Therefore, thevisibility of an image at a low gray level from the side view can beimproved.

In addition, the liquid crystal molecule 31 c 1 disposed in the firstsub-field area EFa is tilted at an azimuth of about 45 degrees to thefirst direction d1, and the liquid crystal molecule 31 c 2 disposed inthe second sub-field area EFb is tilted at an azimuth of about 135degrees to the first direction d1 (that is, an included angle betweenthe liquid crystal molecule 31 c 2 and a virtual line extending in thefirst direction d1 is about 45 degrees). This can improve visibility ofan image at a low gray level and effectively minimize a reduction intransmittance at a high gray level.

FIG. 12 is a graph illustrating transmittance versus gray level of anexemplary embodiment of an LCD device. The horizontal axis of the graphrepresents gray level, and the vertical axis represents transmittance T.Reference numeral 1 indicates transmittance with respect to gay level ata front view of the LCD device, and reference numerals 2 and 3 indicatetransmittances with respect to gray level at a side view of the LCDdevice. Here, reference numeral 2 indicates an LCD device according to acomparative example, and reference numeral 3 indicates an LCD deviceaccording to an exemplary embodiment.

Referring to FIG. 12, at low gray levels of an image, the LCD device 3according to the exemplary embodiment has improved visibility at theside view because the transmittance of the LCD device 3 according to theexemplary embodiment is relatively close to the transmittance 1 withrespect to gray level at the front view. In addition, at high graylevels of an image, the LCD device 3 according to the exemplaryembodiment has even higher transmittance than the LCD device 2 accordingto the comparative example.

Table 1 below shows the transmittance and visibility index (“GDI”) ofeach of the LCD device 3 according to the exemplary embodiment and theLCD device 2 according to the comparative example.

TABLE 1 Exemplary Comparative Embodiment example Transmittance (%) 104100 Visibility index (GDI) 0.425 0.444

Referring to Table 1 and FIG. 12, the LCD device 3 according to theexemplary embodiment has higher transmittance and lower visibility indexthan the LCD device 2 according to the comparative example. Therefore,the LCD device 3 according to the exemplary embodiment has improvedlateral visibility.

FIGS. 13 through 16 are schematic plan views of other exemplaryembodiments of pixels included in LCD devices. A description of elementsand features identical to those described above with reference to FIGS.1 through 12 will be omitted. In addition, elements identical to thosedescribed above will be indicated by the same reference characters. Forease of description, FIGS. 13 through 16 illustrates mainly a pixelelectrode PE and a shielding electrode 180.

Referring to FIG. 13, a first sub-pixel electrode SPE1 may have the sameshape as a third sub-pixel electrode SPE31. The third sub-pixelelectrode SPE31 may include a third plate portion SPE31 a and aplurality of third branch portions SPE31 b. A second sub-pixel electrodeSPE2 may have the same shape as a fourth sub-pixel electrode SPE41. Thefourth sub-pixel electrode SPE41 may include a fourth plate portion SPE4a and a plurality of fourth branch portions SPE4 b. A vertical length h1of the first sub-pixel electrode SPE1 is smaller than a vertical lengthh2 of the second sub-pixel electrode SPE2. A vertical length h3 of thethird sub-pixel electrode SPE31 is smaller than a vertical length h4 ofthe fourth sub-pixel electrode SPE41. In an exemplary embodiment,horizontal lengths l1 through l4 of the first through fourth sub-pixelelectrodes SPE1 through SPE41 may be substantially equal to each other,for example.

A first sub-shielding electrode 180 aA, which corresponds to the firstsub-shielding electrode 180 a in FIG. 4, may include a first area 180 a1, a second area 180 a 2, a third area 180 a 3, and a fourth area 180 a4. The first through fourth areas 180 a 1 through 180 a 4 may bearranged along the first direction d1 with an order of the first throughfourth areas 180 a 1 through 180 a 4. A first width w1 of the first area180 a 1 may be substantially equal to a third width w3 of the third area180 a 3 along the second direction d2. A second width w2 of the secondarea 180 a 2 may be substantially equal to a fourth width w4 of thefourth area 180 a 4 along the second direction d2. That is, the secondarea 180 a 2 and the fourth area 180 a 4 of the first sub-shieldingelectrode 180 a may be recessed in the third direction d3.

The first through fourth sub-pixel electrodes SPE1 through SPE41 mayface the first through fourth areas 180 a 1 through 180 a 4 of the firstsub-shield electrode 180 aA, respectively.

The first sub-pixel electrode SPE1 and the third sub-pixel electrodeSPE31 may not overlap a black matrix BM. In addition, at least part ofeach of the second sub-pixel electrode SPE2 and the fourth sub-pixelelectrode SPE41 may overlap the black matrix BM.

That is, while the space between the first sub-shielding electrode 180aA and each of the second sub-pixel electrode SPE2 and the thirdsub-pixel electrode SPE31 is overlapped by the black matrix BM in FIGS.1 through 12, a space between the first sub-shielding electrode 180 aAand each of the second sub-pixel electrode SPE2 and the fourth sub-pixelelectrode SPE41 is overlapped by the black matrix BM.

However, as long as one of at least two sub-pixel electrodes included ina pixel electrode overlaps the black matrix BM and the other sub-pixelelectrode does not overlap the black matrix BM, the arrangement of thesub-pixel electrodes and the shape of the first sub-shielding electrode180 aA are not limited to those illustrated in the drawing.

Referring to FIG. 14, a second sub-pixel electrode SPE21 and a thirdsub-pixel electrode SPE32 may extend further in the second direction d2than the first sub-pixel electrode SPE1 and the fourth sub-pixelelectrode SPE4. The second sub-pixel electrode SPE21 may include asecond plate portion SPE21 a and a plurality of second branch portionsSPE21 b. The third sub-pixel electrode SPE32 may include a third plateportion SPE32 a and a plurality of third branch portions SPE32 b. Afirst sub-shielding electrode 180 aB and a second sub-shieldingelectrode 180 bA correspond to the first sub-shielding electrode 180 aand the second sub-shielding electrode 180 b in FIG. 4 respectively.Accordingly, the second sub-shielding electrode 180 bA may include areashaving different widths which correspond to the second sub-pixelelectrode SPE21 and the third sub-pixel electrode SPE32. The secondsub-shielding electrode 180 bA overlaps the second scan line SL2 whichis electrically connected to the gate electrode GE in the directionperpendicular to the major surface plane defining the lower substrate110. That is, a first area 180 b 1 having a first width w11 and a secondarea 180 b 2 having a second width w21 may be located in the secondsub-shielding electrode 180 bA. The first width w11 may be greater thanthe second width w21 in the second direction d2.

Although not illustrated in the drawing, the second sub-pixel electrodeSPE21 and the third sub-pixel electrode SPE32 may extend further alongeach of the second direction d2 and the third direction d3. In thiscase, each of a first sub-shielding electrode 180 aB and the secondsub-shielding electrode 180 bA may include areas having different widthscorresponding to the sizes of the sub-pixel electrodes.

Referring to FIG. 15, a horizontal length I11 of a first sub-pixelelectrode SPE11 may be different from a horizontal length I21 of asecond sub-pixel electrode SPE22 in the first direction d1. Morespecifically, in an exemplary embodiment, the horizontal length I11 ofthe first sub-pixel electrode SPE11 may be about 38.5 μm, for example.In an exemplary embodiment, the horizontal length l21 of the secondsub-pixel electrode SPE22 may be about 41.5 μm, for example. Ahorizontal length l31 of a third sub-pixel electrode SPE33 may be equalto the horizontal length l21 of the second sub-pixel electrode SPE22,and a horizontal length l41 of a fourth sub-pixel electrode SPE41 may beequal to the horizontal length l11 of the first sub-pixel electrodeSPE11. The first through fourth sub-pixel electrodes SPE11 through SPE41may include first through fourth plate portions SPE11 a through SPE41 aand a plurality of first through fourth branch portions SPE11 b throughSPE41 b respectively. The first sub-shielding electrode 180 aCcorresponds to the first sub-shielding electrode 180 a in FIG. 4.

A distance t2 between the first sub-pixel electrode SPE11 and the secondsub-pixel electrode SPE22 may be about 5 μm in an exemplary embodiment,for example. In an exemplary embodiment, a distance between the secondsub-pixel electrode SPE22 and the third sub-pixel electrode SPE33 and adistance between the third sub-pixel electrode SPE33 and the fourthsub-pixel electrode SPE41 may be equal to the distance t2 between thefirst sub-pixel electrode SPE11 and the second sub-pixel electrodeSPE22.

That is, an electric field at a low gray level can be reinforced byforming the horizontal length l11 of the first sub-pixel electrode SPE11smaller than the horizontal length l22 of the second sub-pixel electrodeSPE22 and increasing the distance t2 between the first sub-pixelelectrode SPE11 and the second sub-pixel electrode SPE22. As a result,lateral visibility can be improved.

Referring to FIG. 16, first through fourth sub-pixel electrodes SPE11through SPE41 may have the same vertical length in the second directiond2. In contrast, the horizontal length l11 of the first sub-pixelelectrode SPE11 may be different from the horizontal length l21 of thesecond sub-pixel electrode SPE23 in the first direction d1. In anexemplary embodiment, the horizontal length l11 of the first sub-pixelelectrode SPE11 may be about 38.5 μm, and the horizontal length l21 ofthe second sub-pixel electrode SPE23 may be about 41.5 μm, for example.The horizontal length l31 of the third sub-pixel electrode SPE34 may beequal to the horizontal length l21 of the second sub-pixel electrodeSPE23, and the horizontal length l41 of the fourth sub-pixel electrodeSPE41 may be equal to the horizontal length l11 of the first sub-pixelelectrode SPE11. The second and third sub-pixel electrodes SPE23 andSPE34 may include second and third plate portions SPE23 a and SPE34 aand a plurality of second and third branch portions SPE23 b throughSPE34 b respectively.

The distance t2 between the first sub-pixel electrode SPE11 and thesecond sub-pixel electrode SPE23 may be about 5 μm in an exemplaryembodiment, for example. A distance between the second sub-pixelelectrode SPE23 and the third sub-pixel electrode SPE34 and a distancebetween the third sub-pixel electrode SPE34 and the fourth sub-pixelelectrode SPE41 may be equal to the distance t2 between the firstsub-pixel electrode SPE11 and the second sub-pixel electrode SPE23 in anexemplary embodiment, for example.

The first sub-shielding electrode 180 aB may be provided to havesubstantially a uniform width in the second direction d2. The secondsub-shielding electrode 180 b may be provided to have substantially auniform width in the second direction d2.

FIG. 17 is a graph illustrating transmittance versus gray level of anexemplary embodiment of the LCD device of FIG. 16. The horizontal axisof the graph represents gray level, and the vertical axis representstransmittance T. Reference numeral 1 indicates transmittance withrespect to gray level at the front view of the LCD device, and referencenumerals 2 and 3 indicate transmittances with respect to gray level atthe side view of the LCD device. Here, reference numeral 2 indicates anLCD device according to a comparative example, and reference numeral 3indicates an LCD device according to an exemplary embodiment.

Table 2 below shows the transmittance and GDI of each of the LCD device3 according to the exemplary embodiment and the LCD device 2 accordingto the comparative example.

TABLE 2 Embodiment Comparative (FIG. 16) example Transmittance (%) 102100 Visibility index (GDI) 0.404 0.444

Referring to Table 2 and FIG. 17, the LCD device 3 according to theexemplary embodiment of FIG. 16 has higher transmittance and lowervisibility index than the LCD device 2 according to the comparativeexample. Therefore, the LCD device 3 according to the exemplaryembodiment has improved lateral visibility.

More specifically, since the area of the first sub-pixel electrode SPE11and the area of the second sub-pixel electrode SPE23 (or the area of thethird sub-pixel electrode SPE34 and the area of the fourth sub-pixelelectrode SPE4) are different, there is a difference involtage-transmittance ratio between the first sub-pixel electrode SPE11and the second sub-pixel electrode SPE23. The difference involtage-transmittance ratio improves lateral visibility of the LCDdevice 3 according to the exemplary embodiment.

FIG. 18 is a schematic plan view of an exemplary embodiment of a pixelincluded in an LCD device of FIG. 1. For ease of description, FIG. 18illustrates mainly the pixel electrode PE, the shielding electrode 180and the first through fourth slit portions SLT1 through SLT4.

Referring to FIG. 18, the first slit portion SLT1 may be the same shapeand size as the fourth slit portion SLT4 in an exemplary embodiment. Thesecond slit portion SLT2 may be the same shape and size as the thirdslit portion SLT3 in an exemplary embodiment. Horizontal lengths of thefirst slit SLT1 through the fourth slit SLT4 may all be the same in thefirst direction d1.

In contrast, horizontal widths ws1 of the first through fourth slitportions SLT1 through SLT4 in the second direction d2 may be differentfrom vertical widths ws2 of the first through fourth slit portions SLT1through SLT4 in the first direction d1. In an exemplary embodiment, thehorizontal widths ws1 of the first through fourth slit portions SLT1through SLT4 may be smaller than the vertical widths ws2 of the firstthrough fourth slit portions SLT1 through SLT4. The vertical widths ws1of the first through fourth slit portions SLT1 through SLT4 may be about3 μm in an exemplary embodiment, for example. The vertical widths ws2 ofthe first through fourth slit portions SLT1 through SLT4 may be about 5μm in an exemplary embodiment, for example.

Since the horizontal widths ws1 of the first through fourth slitportions SLT1 through SLT4 are smaller than the vertical widths ws2 ofthe first through fourth slit portions SLT1 through SLT4, a strongelectric field can be provided in the first direction d1 and in adirection opposite to the first direction d1. As a result, lateralvisibility at a low gray level can be improved.

FIG. 19 is a schematic plan view of another exemplary embodiment of apixel included in an LCD device.

Referring to FIG. 19, first through fourth slit portions SLT1 throughSLT4 may all have the same shape.

That is, horizontal widths ws1 of the first through fourth slit portionsSLT1 through SLT4 in the second direction d2 may be different fromvertical widths ws2 of the first through fourth slit portions SLT1through SLT4 in the first direction d1. More specifically, thehorizontal widths ws1 of the first through fourth slit portions SLT1through SLT4 may be smaller than the vertical widths ws2 of the firstthrough fourth slit portions SLT1 through SLT4. The horizontal widthsws1 of the first through fourth slit portions SLT1 through SLT4 may beabout 3 μm in an exemplary embodiment, for example. The vertical widthsws2 of the first through fourth slit portions SLT1 through SLT4 may beabout 5 μm in an exemplary embodiment, for example. The second sub-pixelelectrode SPE24 may include second plate portions SPE24 a and aplurality of second branch portions SPE24 b respectively. The second andthird slit portions SLT21 and SLT31 correspond to the second and thirdslit portions SLT2 and SLT3 in FIG. 1 respectively.

FIG. 20 is a graph illustrating transmittance versus gray level of anexemplary embodiment of the LCD device of FIG. 19. The horizontal axisof the graph represents gray level, and the vertical axis representstransmittance T. Reference numeral 1 indicates transmittance withrespect to gray level at the front view of the LCD device, and referencenumerals 2 and 3 indicate transmittances with respect to gray level atthe side view of the LCD device. Here, reference numeral 2 indicates anLCD device according to a comparative example, and reference numeral 3indicates an LCD device according to an exemplary embodiment.

Table 3 below shows the transmittance and GDI of each of the LCD device3 according to the exemplary embodiment and the LCD device 2 accordingto the comparative example.

TABLE 3 Embodiment Comparative (FIG. 19) example Transmittance (%) 95100 Visibility index (GDI) 0.384 0.444

Referring to Table 3 and FIG. 20, the LCD device 3 according to theexemplary embodiment of FIG. 19 is not greatly different intransmittance from the LCD device 2 according to the comparative examplebut has a lower visibility index than the LCD device 2 according to thecomparative example. Therefore, the LCD device 3 according to theexemplary embodiment has improved lateral visibility.

Since the horizontal widths ws1 of the first through fourth slitportions SLT11 through SLT41 are smaller than the vertical widths ws2 ofthe first through fourth slit portions SLT11 through SLT41, a strongelectric field can be provided in the first direction d1 and in thedirection opposite to the first direction d1. As a result, lateralvisibility at a low gray level can be improved.

Although not illustrated in the drawings, the pixel PX illustrated inFIG. 1 can be applied to a pixel displaying a blue color in an exemplaryembodiment. However, the pixel PX illustrated in FIG. 1 can also beapplied to a pixel displaying green or red colors.

According to embodiments of the inventive concept, a reduction inaperture ratio can be effectively minimized.

In addition, lateral visibility can be improved.

Furthermore, a reduction in transmittance at a high gray level can beeffectively minimized.

Although certain exemplary embodiments and implementations have beendescribed herein, other embodiments and modifications will be apparentfrom this description. Accordingly, the inventive concept is not limitedto such embodiments, but rather to the broader scope of the presentedclaims and various obvious modifications and equivalent arrangements.

What is claimed is:
 1. A liquid crystal display (LCD) device comprising:a first substrate; a pixel electrode which is disposed on the firstsubstrate and comprises a first sub-pixel electrode and a secondsub-pixel electrode adjacent to the first sub-pixel electrode along afirst direction; and a shielding electrode which is disposed on the samelayer as the pixel electrode and comprises a first area having a firstwidth and a second area having a second width which is smaller than thefirst width along a second direction which crosses the first direction,wherein the first sub-pixel electrode is adjacent to the first area ofthe shielding electrode along the second direction, and the secondsub-pixel electrode is adjacent to the second area of the shieldingelectrode along the second direction.
 2. The LCD device of claim 1,further comprising: a second substrate which faces the first substrate;and a black matrix which is disposed on the second substrate, whereinthe black matrix does not overlap the first sub-pixel electrode andoverlaps at least part of the second sub-pixel electrode in a directionperpendicular to a major surface plane defining the first substrate. 3.The LCD device of claim 2, further comprising: a first spacing areawhich is disposed between the first sub-pixel electrode and the firstarea of the shielding electrode; and a second spacing area which isdisposed between the second sub-pixel electrode and the second area ofthe shielding electrode, wherein the black matrix completely overlapsthe second spacing area in the direction perpendicular to the majorsurface plane defining the first substrate.
 4. The LCD device of claim3, wherein the black matrix does not overlap the first spacing area inthe direction perpendicular to the major surface plane defining thefirst substrate.
 5. The LCD device of claim 3, further comprising aplurality of liquid crystal molecules which are disposed in the secondspacing area, wherein the liquid crystal molecules completely overlapthe black matrix in the direction perpendicular to the major surfaceplane defining the first substrate.
 6. The LCD device of claim 1,wherein the area of the first sub-pixel electrode is smaller than thatof the second sub-pixel electrode.
 7. The LCD device of claim 1, whereineach of the first sub-pixel electrode and the second sub-pixel electrodehas a vertical length parallel to the second direction, wherein thevertical length of the first sub-pixel electrode is smaller than that ofthe second sub-pixel electrode.
 8. The LCD device of claim 1, whereineach of the first sub-pixel electrode and the second sub-pixel electrodehas a horizontal length parallel to the first direction, wherein thehorizontal length of the first sub-pixel electrode is smaller than thatof the second sub-pixel electrode.
 9. The LCD device of claim 1, furthercomprising a common electrode which defines a first slit portionoverlapping the first sub-pixel electrode in the direction perpendicularto the major surface plane defining first substrate and a second slitportion overlapping the second sub-pixel electrode in the directionperpendicular to the major surface plane defining the first substrate,wherein each of the first slit portion and the second slit portion iscross-shaped.
 10. The LCD device of claim 9, wherein each of the firstslit portion and the second slit portion has a vertical portion parallelto the second direction, wherein a vertical length of the verticalportion of the first slit portion is smaller than a vertical length ofthe vertical portion of the second slit portion in the second direction.11. The LCD device of claim 9, wherein the first slit portion comprisesa horizontal portion parallel to the first direction and a verticalportion parallel to the second direction, and the second slit portioncomprises a horizontal portion parallel to the first direction and avertical portion parallel to the second direction, wherein a width ofthe horizontal portion of the first slit portion in the second directionis narrower than a width of the vertical portion of the first slitportion in the first direction, and a width of the horizontal portion ofthe second slit portion in the second direction is narrower than a widthof the vertical portion of the second slit portion in the firstdirection.
 12. The LCD device of claim 1, further comprising: a firstscan line which extends in the first direction and overlaps theshielding electrode in the direction perpendicular to the major surfaceplane defining the first substrate; and at least part of the secondsub-pixel electrode overlaps the first scan line in the directionperpendicular to the major surface plane defining the first substrate.13. A liquid crystal display (LCD) device comprising: a first substrate;a pixel electrode which is disposed on the first substrate and comprisesa first sub-pixel electrode and a second sub-pixel electrode adjacent tothe first sub-pixel electrode in a first direction; a second substratewhich faces the first substrate; and a black matrix which is disposed onthe second substrate, wherein the black matrix does not overlap thefirst sub-pixel electrode and overlaps at least part of the secondsub-pixel electrode in a direction perpendicular to a major surfaceplane defining the first substrate.
 14. The LCD device of claim 13,further comprising a shielding electrode which is disposed on the samelayer as the pixel electrode and comprises a first area having a firstwidth and a second area having a second width which is smaller than thefirst width along a second direction which crosses the first direction,wherein the first sub-pixel electrode faces the first area of theshielding electrode along the second direction, and the second sub-pixelelectrode faces the second area of the shielding electrode along thesecond direction.
 15. The LCD device of claim 14, further comprising: afirst spacing area which is disposed between the first sub-pixelelectrode and the first area; and a second spacing area which isdisposed between the second sub-pixel electrode and the second area,wherein the black matrix completely overlaps the second spacing area inthe direction perpendicular to the major surface plane defining thefirst substrate.
 16. The LCD device of claim 15, wherein the blackmatrix does not overlap the first spacing area in the directionperpendicular to the major surface plane defining the first substrate.17. The LCD device of claim 15, further comprising a plurality of liquidcrystal molecules which are located in the second spacing area, whereinthe liquid crystal molecules completely overlap the black matrix in thedirection perpendicular to the major surface plane defining the firstsubstrate.
 18. The LCD device of claim 13, wherein the area of the firstsub-pixel electrode is smaller than that of the second sub-pixelelectrode.
 19. The LCD device of claim 13, wherein each of the firstsub-pixel electrode and the second sub-pixel electrode has a verticallength parallel to a second direction which crosses the first direction,wherein the vertical length of the first sub-pixel electrode is smallerthan that of the second sub-pixel electrode.
 20. The LCD device of claim13, further comprising a common electrode which defines a first slitportion overlapping the first sub-pixel electrode in the directionperpendicular to the major surface plane defining the first substrateand a second slit portion overlapping the second sub-pixel electrode inthe direction perpendicular to the major surface plane defining thefirst substrate, wherein each of the first slit portion and the secondslit portion has a vertical portion parallel to a second directioncrossing the first direction, wherein the vertical length of thevertical portion of the first slit portion is smaller than a verticallength of the vertical portion of the second slit portion in the seconddirection.